VENICE — Among other things, Florida’s rainy season causes golf game cancellations, more frequent lawn mowing and the occasional “No swim” advisory at area beaches.
It’s happened more than a dozen times in South County since 2012, some years more than others.
One was issued Thursday for seven county beaches, including five in the Venice area. As usual, the reason was elevated levels of enterococcus bacteria.
All of the county’s 16 beaches were tested on Monday, and those with elevated levels of the bacteria were tested again on Wednesday, a chart at OurGulfEnvironment.net shows.
The seven beaches for which the advisory was issued were still in the “poor” range, which is anything more than 70 “colony-forming units” per 100 milliliters, or about 3.4 ounces. Advisories were lifted at all but three beaches — two in Venice — Friday afternoon.
Though the beaches still under an advisory remain open, beachgoers are advised to stay out of the water and not to consume any shellfish from an area where a no-swim advisory is in place. It’s OK to eat fin fish, though, if they’ve been filleted.
The next testing will be on Monday.
The bacteria pose a potential health problem to people who go into the water, especially if they’re young, elderly or have a weakened immune system, a Florida Department of Health-Sarasota news release states.
If ingested or encountered through an open wound or sore, they can cause endocarditis, urinary tract infections, prostatitis, intra-abdominal infections, cellulitis and wound infection, MerckManual.com says.
These conditions can be hard to treat, because of antibiotic resistance. Prevention, by avoiding contact with potentially tainted water, is the best course of action.
Enterococcus bacteria occur naturally in the environment and are found in the intestines of mammals, according to the National Institutes of Health. They can appear in sewage, soil and water through fecal contamination.
Elevated levels of the bacteria have led to the issuance of advisories as early as January and as late as December, according to Gondolier archives, but they most commonly occur when heavy rains cause contaminants to wash into waterways that lead to the Gulf.
Potential sources include pet waste; livestock; birds, a frequently blamed culprit; wildlife, stormwater runoff; and human sewage from failed septic systems and sewage spills, according to DOH, though it notes that there have been no recent sewage spills within a mile of the posted beaches.
The city has fewer than 50 properties with septic tanks, but there are many in Nokomis and South Venice.
To reduce the risk of bacteria getting into the Gulf, DOH’s advisory includes a warning not to allow pets to roam on beaches and in park areas, unless designated for pets, and to pick up pet waste, and not to allow children in diapers or anyone with diarrhea in the water.
However, the current contamination, like most, is believed to be a result of natural causes.
The rapid response team from Sarasota County and city of Venice observed a line of decaying algae around the rocks and along the shoreline of the affected beaches, DOH says.
Such “wrack lines” of decaying algae collect bacteria around the rocks and along the shoreline. Birds and animals feed in the area and can spread the bacteria as well as add to it.
Wave action can also churn the wrack lines, distributing the bacteria there.
Although it’s most commonly associated with outbreaks of red tide, fertilizer also has a connection to enterococcus. NIH studies show both a higher bacteria count where fertilizer has been applied and a higher degree of antibiotic resistance in the bacteria.
County residents are currently in a blackout period that largely bans the use of any fertilizer that contains nitrogen or phosphorous. It runs from June 1 to Sept. 30 each year, though North Port commissioners are considering whether to start the city’s ban 30 to 60 days earlier.